Thirty-five strains of Bifidobucrrrium species obtained from Type Culture collections, or isolated from the faeces of human subjects. were differentiated using an improved ribotyping method in which bifidobacterial cells were embedded in agarose plugs prior to lysis. Twenty ribotypes were detected among the 35 isolates on the basis of BumHI, NarI, and PvuII digests of bifidobacterial DNA hybridised to a 32P-labelled 16s rDNA probe amplified from B. icfantis ATCC 15697Keywords: bifidobacteria; ribotyping.